<?php

class Skjb_Office_Spreadsheet
{
    public $sheets = array();
    
    public function __construct($filename = null)
    {
        
    }
    
    public function addSheet($sheet = null)
    {
        if ($sheet === null) {
            $sheet = new Skjb_Office_Spreadsheet_Sheet();
        }
        
        $this->sheets[] = $sheet;
        
        return $sheet;
    }
}